The feel-good chapters of Juan Nicasio's major-league story are heroic and heartwarming. He overcame the chilling line drive to his head that led to a broken neck in August 2011. He recovered, only to injure his knee in early June last season.

What the tale has been missing is success on the mound. Nicasio began adding that chapter Sunday afternoon at breezy Coors Field.

"He's been through a lot the last two years," said Rockies pitching coach Jim Wright. "He needed a breakthrough game. Maybe this was it."

Nicasio, a 26-year-old right-hander, pitched six scoreless innings and allowed only three hits as the Rockies beat the defending World Series champion Giants 5-0 in front of 47,494 fans. After blowing a six-run lead in a demoralizing 8-6 loss Thursday, the Rockies rebounded to take three straight from the Giants and win the four-game series.

Rockies starting pitcher Juan Nicasio turns to throw out San Francisco's Barry Zito to end the top of the fifth inning. More photos. (David Zalubowski, The Associated Press)

Make no mistake, when Nicasio trotted out to the mound, there was a lot of weight on his broad shoulders.

Not only was Nicasio the key to the Rockies' chance to win a rare series from the Giants, he was pitching to secure his fragile spot in the rotation.

Nicasio responded in splendid fashion, pitching one of the best games of his career. Plus, he added an effective two-seam, sinking fastball to his repertoire that could make a major difference moving forward.

Nicasio improved to 4-1 and lowered his ERA to 4.47. He said he didn't put added pressure on himself. "I just went out to pitch," he said. "I just wanted to do my job, throw strikes down in the zone. I threw my fastballs for strikes. That was a good start."

Nicasio's pinnacle moment arrived with two outs in the sixth inning. The Giants had runners on second and third, thanks to an error on a routine grounder booted by second baseman Josh Rutledge. Just before Nicasio's critical 3-2 pitch to Giants first baseman Brandon Belt, veteran catcher Yorvit Torrealba came to the mound for a quick consultation. Nicasio then threw a biting slider that Belt swung over the top of for an inning-ending strikeout.

Rockies shortstop Troy Tulowitzki jumps in the air as he throws to put out the Giants' Brandon Crawford in the fourth inning. More photos. (David Zalubowski, The Associated Press)

Torrealba, catching Nicasio for the first time this season, provided an exclamation point with a pumped fist.

"I said to him, 'You need to pick somebody up, and that would be Leo,' " Torrealba said, making a joking Leonardo DiCaprio reference to Rutledge, who somewhat resembles the actor. "I won't make any signs, I just want you to throw a 3-2 slider. If we walk him, we will get the next guy. And he was able to throw it down like I wanted and we got out of that spot. It was huge."

Nicasio whiffed five in all and walked only one. He needed just 89 pitches to get through six innings. Mixing in his two-seamer with his mid-90s, four-seam fastball for the first time in a game, he got 11 groundball outs.

Wright said Nicasio added the two-seamer while playing catch in Chicago last Tuesday, a day after Nicasio lost to the Cubs, giving up five runs and eight hits in six innings.

"He added a little two-seam action on his fastball that helped him," Wright said. "He threw it for the first time ever, in Chicago, just before this start. There is some natural movement with the pitch. He had the courage to take it out there."

San Francisco starter Barry Zito had been a left-handed Rubik's Cube for the Rockies, owning a 2.47 ERA against them coming into Sunday. But the Rockies finally cracked the puzzle. Colorado scored two runs in the fifth inning on a leadoff single by Dexter Fowler and an RBI double off the right-field wall by Carlos Gonzalez. CarGo scored on a base hit up the middle by Jordan Pacheco to increase Colorado's lead to 3-0.

"We made him earn his outs," Rockies manager Walt Weiss said of Zito. "To his credit, I thought he battled really well, hung in there and stayed in the game for a while, worked out of some trouble. But I think we had a nice approach offensively."

The Rockies struck quickly. Eric Young Jr. led off the first with a single, stole second and advanced to third on Zito's wild pitch. Gonzalez poked a single to right field to drive in Young.

Zito hadn't suffered a loss to the Rockies since Sept. 25, 2008, and was 6-0 with a 2.96 ERA in his last 10 starts against them. But he got beaten up Sunday: five runs on 11 hits in 5 innings.

Giant progress

The Rockies have foundered against the Giants in recent years, but their 5-0 victory Sunday was a giant step in the right direction. A closer look:

The Rockies won three straight games vs. the Giants after losing 10 straight.

Colorado got its first series win over the Giants in the last 11 series played.

The last time the Rockies shut out the Giants at Coors Field was Sept. 1, 2008.

The Rockies beat left-hander Barry Zito for the first time since Sept. 25, 2008.

The Rockies scored 31 runs in four games against a gantlet of star San Francisco Giants pitchers. Now they get to face 23-year-old Arizona ace Patrick Corbin. How good has the lefty been? He's the only pitcher in Diamondbacks history to begin a season with eight consecutive starts, going at least six innings with two or fewer runs allowed in each game. In his last start, he pitched seven scoreless innings against the Braves, allowing three hits and five walks while striking out five. Coors Field, however, has been a house of horrors for Corbin. In two starts there, the Rockies are hitting .419 against him and he's 0-1 with an 11.00 ERA over nine innings.

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